This invention relates to absorbent liners for nether garments such as, for example, sanitary napkins, panty shields and the like. The function of such products is to be placed against the body and, specifically, between the body and the nether garment whereby the product may absorb and retain fluid exuded from the body and hence protect the nether garment from soiling or staining.
Such products now on the market are generally made in a flat or planar form. However, in order to function properly, the product should be held in intimate contact with the body. Since, in most cases, the configurations of the particular parts of the body against which the products are to be placed in use are not flat, it is necessary to distort these originally flat products into nonplanar configurations. For example, panty shields now on the market are flat and planar, yet are designed to fit, by adhesive attachment, to the crotch portion of an undergarment and to closely conform to the vaginal area of the wearer. Clearly, the flat product must be distorted to conform to the generally arcuate shape of the body, i.e., the product must assume a non-planar, arcuate shape being concave inward with respect to the body contacting surface.
The necessary distorting of such originally flat products has resulted in unsatisfactory performance. In particular, when so distorting these products which are generally made up of one or more layers of fibrous absorbent material, creases and folds result causing great discomfort to the wearer. Additionally, such creases and folds cause portions of the product to stand away from close contact with the body and hence, the primary absorbing function of the product is greatly impaired.
Suggestions already exist for manufacturing arcuate absorbent products, yet to date, no such product has met with any commercial success. This failure of prior art suggestions is generally due to the fact that the kinds of absorbent products considered herein are of the disposable variety and must be manufactured at great speed and for an extremely low unit cost in order to be commercially viable. The very nature of a non-planar product has heretofore been incompatible with high speed, straight line, continuous manufacturing processes. Additionally, the methods devised by prior art suggestions require costly processing steps and raw materials and hence, have been unacceptable.
A specific example of such prior art suggestion is that disclosed in U.S. Pat. No. 3,262,451 issued to Edward A. Morse on July 26, 1966. Described therein is an arcuate absorbent pad which is first manufactured in a planar shape but upon subsequent treatment, takes on the desired non-planar arcuate shape. This change in shape is accomplished by adhering to the absorbent pad or embedding within the absorbent pad a layer of so-called "heat-shrinkable" polymeric film. Such film has the property of shrinking when subjected to a heating. According to the method of Morse, the flat product comprising the absorbent pad and film is subjected to a heating step which shrinks the film and induces the product to assume an arcuate shape. Unfortunately, this product and method has not had commercial success primarily because of the above mentioned factors, to wit: the heating step introduces complexities and expense into the high speed manufacture of such a product and the special film is relatively expensive when compared to materials normally employed in such products. Accordingly, there is still an unfulfilled need for a simple, economically manufactured, non-planar, arcuate absorbent nether garment liner.